There is a widespread need for sampling plates such as those which, when used in conjunction with a measurement device, enable a diabetes patient to know their blood sugar levels—i.e. the concentration of glucose in their blood.
Traditional sampling plates function by receiving a spotted blood sample and directing at least some of the blood to a testing zone. The testing zone typically takes the form of a recess or well containing a quantity of glucose oxidase which chemically reacts with the blood to an extent and at a rate determined by the glucose concentration in the blood. The testing zone is typically furnished with a pair of electrode terminals which are conveniently bridged by the reaction mixture of the blood and glucose oxidase so as to allow for electrochemical readings by a corresponding measurement device. The electrochemical readings then provide an indication of blood glucose levels.
A problem with such traditional sampling plates is that they are often unreliable when overfilled, meaning that care is needed when applying blood samples to the sampling plate. This can be inconvenient for less dextrous individuals. Another problem is that traditional sampling plates often give poor distribution of blood samples, often providing testing zones with an inconsistent measure of blood. Another problem with traditional sampling plates is that a blood sample in one testing zone is linked along a fluid path to a blood sample in another testing zone, which gives rise to inaccurate measurements, particularly in electrochemical systems. Another problem is that blood spreading in and to the testing zone is often slow and/or non-uniform. For instance, blood spreading is often biased in the direction of an initial blood flow courtesy of surface tension. Sometimes a blood sample will not spread throughout the testing zone, and consequently measurements may be inaccurate or unreliable.
It is an object of the present invention to provide an improved sampling plate.